“Breakthrough Therapy” status for Portola’s andexanet alfa

USA-based Portola Pharmaceuticals (Nasdaq: PTLA) has been granted “Breakthrough Therapy” designation by the US Food and Drug Administration for andexanet alfa, its investigational Factor Xa inhibitor antidote.

The FDA designation is intended to expedite the development and review of drugs for serious or life-threatening conditions. Portola is pursuing an accelerated approval pathway for andexanet alfa, a first-in-class agent, and plans to initiate registration-enabling studies in 2014. By the year 2020, Portola estimates that the number of patients presenting to the hospital who could benefit from an antidote could approach 500,000 in the USA, Japan and the five largest European Union countries alone.

"The FDA's decision to designate andexanet alfa as a breakthrough therapy reaffirms the urgent need for an antidote to Factor Xa inhibitors, and we believe it demonstrates that andexanet alfa's properties and data distinguish it from currently used agents or others in development," said William Lis, Portola's chief executive, adding: "Pro-coagulant agents being used in the absence of an antidote are unproven, have limited biological rationale for their effectiveness to reverse Factor Xa inhibitors, and have been shown to cause serious blood clots. Therefore, andexanet alfa marks an important advance in the field, and our goal is to bring it to market as quickly as possible."